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Commit 9b760fd8 authored by Douglas Gilbert's avatar Douglas Gilbert Committed by Martin K. Petersen
Browse files

scsi: scsi_debug: add cdb_len parameter 



While testing "sd: Micro-optimize READ / WRITE CDB encoding" patches it
was helpful to check various code paths associated with READ/WRITE 6, 10
and 16 byte cdb variants. There seems to be no user space "knobs" to
twiddle use_10_for_rw and friends in the scsi_device structure.  So add
a parameter to scsi_debug called "cdb_len" for this purpose.

[mkp: fixed typo]

Signed-off-by: default avatarDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: default avatarBart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 4b1d8e78

drivers/scsi/scsi_debug.c

+87 −5
Original line number Diff line number Diff line
@@ -6,7 +6,7 @@ 
 *  anything out of the ordinary is seen.

 * ^^^^^^^^^^^^^^^^^^^^^^^ Original ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

 *

 * Copyright (C) 2001 - 2016 Douglas Gilbert

 * Copyright (C) 2001 - 2017 Douglas Gilbert

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by
@@ -61,8 +61,8 @@ 
#include "scsi_logging.h"



/* make sure inq_product_rev string corresponds to this version */

#define SDEBUG_VERSION "1.86"

static const char *sdebug_version_date = "20160430";

#define SDEBUG_VERSION "0187"	/* format to fit INQUIRY revision field */

static const char *sdebug_version_date = "20171202";



#define MY_NAME "scsi_debug"
@@ -105,6 +105,7 @@ static const char *sdebug_version_date = "20160430"; 
 * (id 0) containing 1 logical unit (lun 0). That is 1 device.

 */

#define DEF_ATO 1

#define DEF_CDB_LEN 10

#define DEF_JDELAY   1		/* if > 0 unit is a jiffy */

#define DEF_DEV_SIZE_MB   8

#define DEF_DIF 0
@@ -571,6 +572,7 @@ static const struct opcode_info_t opcode_info_arr[SDEB_I_LAST_ELEMENT + 1] = { 


static int sdebug_add_host = DEF_NUM_HOST;

static int sdebug_ato = DEF_ATO;

static int sdebug_cdb_len = DEF_CDB_LEN;

static int sdebug_jdelay = DEF_JDELAY;	/* if > 0 then unit is jiffies */

static int sdebug_dev_size_mb = DEF_DEV_SIZE_MB;

static int sdebug_dif = DEF_DIF;
@@ -797,6 +799,61 @@ static int scsi_debug_ioctl(struct scsi_device *dev, int cmd, void __user *arg) 
	/* return -ENOTTY; // correct return but upsets fdisk */

}



static void config_cdb_len(struct scsi_device *sdev)

{

	switch (sdebug_cdb_len) {

	case 6:	/* suggest 6 byte READ, WRITE and MODE SENSE/SELECT */

		sdev->use_10_for_rw = false;

		sdev->use_16_for_rw = false;

		sdev->use_10_for_ms = false;

		break;

	case 10: /* suggest 10 byte RWs and 6 byte MODE SENSE/SELECT */

		sdev->use_10_for_rw = true;

		sdev->use_16_for_rw = false;

		sdev->use_10_for_ms = false;

		break;

	case 12: /* suggest 10 byte RWs and 10 byte MODE SENSE/SELECT */

		sdev->use_10_for_rw = true;

		sdev->use_16_for_rw = false;

		sdev->use_10_for_ms = true;

		break;

	case 16:

		sdev->use_10_for_rw = false;

		sdev->use_16_for_rw = true;

		sdev->use_10_for_ms = true;

		break;

	case 32: /* No knobs to suggest this so same as 16 for now */

		sdev->use_10_for_rw = false;

		sdev->use_16_for_rw = true;

		sdev->use_10_for_ms = true;

		break;

	default:

		pr_warn("unexpected cdb_len=%d, force to 10\n",

			sdebug_cdb_len);

		sdev->use_10_for_rw = true;

		sdev->use_16_for_rw = false;

		sdev->use_10_for_ms = false;

		sdebug_cdb_len = 10;

		break;

	}

}



static void all_config_cdb_len(void)

{

	struct sdebug_host_info *sdbg_host;

	struct Scsi_Host *shost;

	struct scsi_device *sdev;



	spin_lock(&sdebug_host_list_lock);

	list_for_each_entry(sdbg_host, &sdebug_host_list, host_list) {

		shost = sdbg_host->shost;

		shost_for_each_device(sdev, shost) {

			config_cdb_len(sdev);

		}

	}

	spin_unlock(&sdebug_host_list_lock);

}



static void clear_luns_changed_on_target(struct sdebug_dev_info *devip)

{

	struct sdebug_host_info *sdhp;
@@ -955,7 +1012,7 @@ static int fetch_to_dev_buffer(struct scsi_cmnd *scp, unsigned char *arr, 


static char sdebug_inq_vendor_id[9] = "Linux   ";

static char sdebug_inq_product_id[17] = "scsi_debug      ";

static char sdebug_inq_product_rev[5] = "0186";	/* version less '.' */

static char sdebug_inq_product_rev[5] = SDEBUG_VERSION;

/* Use some locally assigned NAAs for SAS addresses. */

static const u64 naa3_comp_a = 0x3222222000000000ULL;

static const u64 naa3_comp_b = 0x3333333000000000ULL;
@@ -1411,6 +1468,8 @@ static int resp_inquiry(struct scsi_cmnd *scp, struct sdebug_dev_info *devip) 
	memcpy(&arr[8], sdebug_inq_vendor_id, 8);

	memcpy(&arr[16], sdebug_inq_product_id, 16);

	memcpy(&arr[32], sdebug_inq_product_rev, 4);

	/* Use Vendor Specific area to place driver date in ASCII hex */

	memcpy(&arr[36], sdebug_version_date, 8);

	/* version descriptors (2 bytes each) follow */

	put_unaligned_be16(0xc0, arr + 58);   /* SAM-6 no version claimed */

	put_unaligned_be16(0x5c0, arr + 60);  /* SPC-5 no version claimed */
@@ -3660,6 +3719,7 @@ static int scsi_debug_slave_configure(struct scsi_device *sdp) 
	blk_queue_max_segment_size(sdp->request_queue, -1U);

	if (sdebug_no_uld)

		sdp->no_uld_attach = 1;

	config_cdb_len(sdp);

	return 0;

}
@@ -4138,6 +4198,7 @@ static int schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip, 
 */

module_param_named(add_host, sdebug_add_host, int, S_IRUGO | S_IWUSR);

module_param_named(ato, sdebug_ato, int, S_IRUGO);

module_param_named(cdb_len, sdebug_cdb_len, int, 0644);

module_param_named(clustering, sdebug_clustering, bool, S_IRUGO | S_IWUSR);

module_param_named(delay, sdebug_jdelay, int, S_IRUGO | S_IWUSR);

module_param_named(dev_size_mb, sdebug_dev_size_mb, int, S_IRUGO);
@@ -4195,6 +4256,7 @@ MODULE_VERSION(SDEBUG_VERSION); 


MODULE_PARM_DESC(add_host, "0..127 hosts allowed(def=1)");

MODULE_PARM_DESC(ato, "application tag ownership: 0=disk 1=host (def=1)");

MODULE_PARM_DESC(cdb_len, "suggest CDB lengths to drivers (def=10)");

MODULE_PARM_DESC(clustering, "when set enables larger transfers (def=0)");

MODULE_PARM_DESC(delay, "response delay (def=1 jiffy); 0:imm, -1,-2:tiny");

MODULE_PARM_DESC(dev_size_mb, "size in MiB of ram shared by devs(def=8)");
@@ -4207,7 +4269,8 @@ MODULE_PARM_DESC(guard, "protection checksum: 0=crc, 1=ip (def=0)"); 
MODULE_PARM_DESC(host_lock, "host_lock is ignored (def=0)");

MODULE_PARM_DESC(inq_vendor, "SCSI INQUIRY vendor string (def=\"Linux\")");

MODULE_PARM_DESC(inq_product, "SCSI INQUIRY product string (def=\"scsi_debug\")");

MODULE_PARM_DESC(inq_rev, "SCSI INQUIRY revision string (def=\"0186\")");

MODULE_PARM_DESC(inq_rev, "SCSI INQUIRY revision string (def=\""

		 SDEBUG_VERSION "\")");

MODULE_PARM_DESC(lbpu, "enable LBP, support UNMAP command (def=0)");

MODULE_PARM_DESC(lbpws, "enable LBP, support WRITE SAME(16) with UNMAP bit (def=0)");

MODULE_PARM_DESC(lbpws10, "enable LBP, support WRITE SAME(10) with UNMAP bit (def=0)");
@@ -4881,6 +4944,24 @@ static ssize_t uuid_ctl_show(struct device_driver *ddp, char *buf) 
}

static DRIVER_ATTR_RO(uuid_ctl);



static ssize_t cdb_len_show(struct device_driver *ddp, char *buf)

{

	return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_cdb_len);

}

static ssize_t cdb_len_store(struct device_driver *ddp, const char *buf,

			     size_t count)

{

	int ret, n;



	ret = kstrtoint(buf, 0, &n);

	if (ret)

		return ret;

	sdebug_cdb_len = n;

	all_config_cdb_len();

	return count;

}

static DRIVER_ATTR_RW(cdb_len);





/* Note: The following array creates attribute files in the

   /sys/bus/pseudo/drivers/scsi_debug directory. The advantage of these
@@ -4920,6 +5001,7 @@ static struct attribute *sdebug_drv_attrs[] = { 
	&driver_attr_ndelay.attr,

	&driver_attr_strict.attr,

	&driver_attr_uuid_ctl.attr,

	&driver_attr_cdb_len.attr,

	NULL,

};

ATTRIBUTE_GROUPS(sdebug_drv);